Patent · US Expired

Image forming electrophotography apparatus and magnetic developing unit

US6487384B2 · kind B2 · utility

3Cited by
2References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 6, 2001
Grant dateNov 26, 2002
Priority date
Expiry dateApr 6, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/0495
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In an image forming apparatus for charging a photosensitive body, changing the light exposure amount in at least three levels at exposure to light, thereby forming an electrostatic image made up of a high-potential part, a low-potential part, and an intermediate-potential part therebetween on the photosensitive body, and normally developing and inversely developing the electrostatic image using toners different in charge polarity for forming two types of toner images on the photosensitive body, a first developer used with a first toner image developing unit has electric resistance changed within 10% in the change range of applied voltage to the developer as the difference between a surface potential of the photosensitive body and a developing bias voltage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.